Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Master → Afrique du Sud → 2011 → The short-term effect of rehabilitation on ecosystem services in the semi-arid succulent Karoo lowlands and the Little Karoo, South Africa

University of Cape Town (2011)

The short-term effect of rehabilitation on ecosystem services in the semi-arid succulent Karoo lowlands and the Little Karoo, South Africa

De Abreu, Petra

Titre : The short-term effect of rehabilitation on ecosystem services in the semi-arid succulent Karoo lowlands and the Little Karoo, South Africa

Auteur : De Abreu, Petra

Université de soutenance : University of Cape Town.

Grade : Master of Science (MS) 2011

Résumé partiel
Ecosystem services (‗the benefits that humans obtain from ecosystems‘) represent a significant contribution to sustaining human well-being. Conservation efforts worldwide are being increasingly focussed outside formally protected areas in order to ensure the protection of biodiversity and ecosystem services. Highlighting ecosystem services attained through the rehabilitation of degraded lands has shown the potential to motivate for conservation on private lands. Conservationists, landowners and society are faced with a fundamental challenge of how to achieve a balance between the utilization of natural capital for improved economic opportunity and the conservation of natural capital for ecosystem service provisioning, both of which are necessary for human well-being. The South African Ostrich Business Chamber through their Long-term Biodiversity Management Strategy is working towards achieving this balance. Degradation from the ostrich industry has been most severe within the Succulent Karoo lowlands in the Little Karoo. Large tracts of land particularly in the eastern Little Karoo have been seriously degraded because of poor ostrich farming practices over the last 150 years. In 2009, the South African Ostrich Business Chamber motivated for an industry switch to environmentally friendly farming systems as well as resting and actively rehabilitating degraded lands in order to ensure the long-term sustainability of the ostrich industry, conserve biodiversity and improve productivity. Without active intervention, severely degraded rangelands may not return to functional states within timescales practical for landowners. While there is potential for landowners to benefit from rehabilitating degraded rangelands, this option is more likely to be realised if the benefits of rehabilitation are investigated and made known. The central aim of this study was to investigate the short-term (c. one year to one-and-a-half years) potential and relative cost of active rehabilitation for increasing ecosystem services on degraded ostrich rangeland. The study firstly evaluated the short-term (one-year) effect of four common rehabilitation techniques (ripping, micro-catchments, sowing seed and mulching) on vegetation recovery, grazing capacity and plant diversity on a severely degraded ostrich farm. In the short term (one-year), ripping (R 0.13/m2) was the least costly method although it was also the least effective. In terms of costs, this was followed by sowing seed (R 0.37/m2), micro-catchments (R 1.54/m2) and mulching (R 2.47/m2). Micro-catchments were the most effective treatment and less costly then mulching. Microcatchments increased palatable plant species richness and plant density ; seed treatments increased palatable species richness, and mulching increased plant diversity (Shannon diversity index). Treatments, however had no effect on perennial vegetation cover or grazing capacity (LSU/ha).

Présentation

Version intégrale

Page publiée le 7 février 2019